1. Field of the Invention
The invention relates to a holding device for receiving switching elements for a command and alert device, with a first housing portion in which a recess for receiving an actuator of a command and alert device is arranged, and with a second housing portion which is arranged on the first housing portion and which continues the recess of the first housing portion.
2. Description of the Related Art
Command and alert devices with holding devices are used in machines or electrical installations that are operated via command devices, such as pushbuttons or selector switches, which act on the control. These command devices are mounted in control panels, operator panels, switching cabinet doors or housing covers. Command devices are generally of modular construction. This means that they consist of an actuator, a holding device, such as an annular nut, or a special mounting holder, and one or more switching elements, which are formed as switching elements of break contacts or make contacts. For mounting, the actuator is generally guided through an opening in the control panel from the front and is mounted from the rear via a fastening part. Switching elements are mechanically secured to the actuator or to the holding device by screws, snap hooks or catches. The electrical connection of the switching elements to the control occurs via connection terminals.
In safety applications, such as an emergency-off command device, it is stipulated that the signal is generated by the opening of positive-opening contacts. This means that, in an unactuated emergency-off command device, the contacts are closed and consequently so is the associated circuit. In the event of a fault or emergency, the break contact is interrupted by striking the emergency-off actuator, which is located in front of the control panel, and this puts the installation or machine in a safe state. However, this only works if the spatial assignment between the actuator and the switching element is ensured. Defective mounting or violent action may have the effect that the switching elements are mechanically separated from the actuator. In this case, the emergency-off command device is no longer operational. That is, if actuated in the event of an emergency, then the contacts are not opened, and consequently the dangerous state is also not rectified. This may lead to fatal harm. Therefore, the secure connection between the actuator and the switching element is of paramount importance.
In addition to the handling, the optics, the fixed seat, the reliability and the quality, a further decisive product feature for a command and alert device is also the reliable connection of a plurality of switching elements to an actuator designed as a crossbar switch or as a selector switch, or to a holding device.